Microtome and attachment therefor



April 12, 1938. D. M. cRooKs 2,113,932

MICROTOME AND ATTACHMENT. THEREFOR Filed April 25, 193e ATTORNEYS Patented Apr. 12, 1938 UNITED smTEsl PATENT FFiCEY 7 Claims;

This invention relates to improvements in microtomes and attachments therefor.

An object of the invention is to provide means by which a microtome may be made to cut a series 5 of sections from two planes of the same specimen in alternate succession. Y

Another object is to provide a device of the above character which may be rreadily attached U to a standard microtome.

Another object is to provide a device of the above character in which the shift from one plane to the other may be readily accomplished by hand.

Another purpose is to provide means by which the device may be retained accurately in each cutting position.

A further object is to provide means by which the shift from each cutting position to the other may be accomplished automatically by the operation of the microtorne. v

Other objects and advantages of the invention will become apparent during the Vcourse of the following description, in connection with the accompanying drawing, in which- Figure 1 is a bottom Vview of the specimen mounting device;

Figure 2 is an end view of the same;

Figure 3 is a view partly in section showing the device in position for cutting inone plane; 1

Figure 4 is a view similar to Figure 3, but show- Ying the platen mounting shifted for cutting in the second plane; 1

Figure 5 shows a typical specimen embedded in a suitable matrix or holding block; Y

Figure 6 shows a succession of sections out from the specimen, Figure 5, in one plane;

. f Figure? illustrates a series of sections cut from .the same specimen alternately in two planes by means of the present invention;

Figure 8 shows the devicelclamped in the head l of a typical microtome; and

Figure 9 illustrates means by which the shifts v from one cutting position to the other may be made automatically by the operation of the mif crotome.

Referring to Figures 1, 2, 3 and 4, the numeral I0 indicates a yoke member having a shank Il adapted to be secured between upper and lower clamping members I2 and I3 Vof the head `-I4 of a microtome I5 such as that shown in Fig. 8. A platen.holder 'I5 is mounted on tapered pivots Il and IB adjustably threaded into the arms of the yokeil.

Formed on theholder I6 is a segment I 9 having at'the extremities of itsarcuatesurface radially extending -stops 23 Yand T2 I adaptedA to engage the yoke I0 when the holder is swung into the positions shown -in Figs. 3 and 4 respectively, thus accurately defining the two cutting positions, the` arc of swing in the device as shown comprisin ninety degrees. -Y

5 A latching plunger 22, Figs. 3 and 4, is slidable Y in a hole 23 in the shank I 0. A spring 24, backed by a retaining plug 25, urges the plunger 22 forward to engage notches`26 and 2l inthe segment I9, by which means the platen holder is retained in either cutting position. A cross pin 22*l spanning a flat 22h on the plunger 22 retains the latter in the shank I l in case the'holder I6 is disassembled from the yokeIO. y

A pin.28 extends laterally from the segment i3 and forms a convenient handle by which to move the holder I6 from either position to the other.

The pin 28 obviously may be located on the other side of the segmentor a pin may be provided on each side.

A platen 29, adjustablysecured to ways 911 on the holder I6, by means of screws 'I4 in slots l5, Fig. 2, has a scored surface 30 adapted to receive and hold a block 3l of paraffin or the like in which is embedded a specimen 32 from which it is desired to cut sections, a typical block and specimen being shown in perspective in Fig. 5.

Referring to Fig. 8, the microtome I5 comprises a base 33 to which is secured a pair of vertical slide rails 3,4. A carriage 35, vertically slidable on rails 34, has secured thereto horizontal guides 36 and 31 between which is disposed a horizontally slidablerblock 38. A drive shaft 39, rotatably mounted in an upright support 40 on the base 33, terinmates in a crank 4I having a crank-pin 42 journalled in the block 38.

f- `The head i4 is slidable horizontally in the car- Vriage 35, and is adapted to be fed to the left by any suitable mechanism 48 which may include a feed screw shaft 43 provided with a ratchet wheel 44. As such feed mechanisms are well known in the art and as their specic details have no bearing on the present invention, no further description of their structure is necessary herein. The clamping members I2 and-|3 of the head i4 `are provided with a clamping screw 45 in order to grip the shank Il as previously described.

An upwardly directedrknife 46 isclamped in Aa support 41 mounted on the base'33.

The operation of the device is as follows: The supporting block or matrix 3l is mounted on the scored surface '30 of the platen 29, the paraffin CIO being softened to'cause itAto adhere firmly thereto. The block 3| is so placed that the corner containing the 'specimen 32 projects beyondthe edge of platen 29 and the shank I I is gripped in the jaws I2 and I3 so as to bring the block 3| adjacent the edge of the knife 46, the platen holder 29 first being swung to the downward position shown in Fig. 4. The shaft 39 is revolved by means of a crank or hand wheel (not shown), causing the crank 4I to reciprocate the carriage 35 vertically in the rails 34, the block 38 sliding horizontally between guides 35 and 3l. By this means the specimen block 3i is carried upward and downward past the knife 46. The feed mechanism 48 advances the head i4 to the left until on a downward stroke of the carriage the knife 46 cuts a slice 49 from the bottom of the block 3 I, as shown in Fig. 4. When the carriage 35 has returned to the top of its stroke, the holder I5 is swung into its upper position, thus revolving the block 3| so as to present its end plane in line with the knife. A revolution of the microtome then causes a slice 59 to be cut from the end of the block, as shown in Fig. 3.

By repeated shifts of the holder I 6 between cutting strokes, it is evident that a series of sections may be cut from the block 3l and specimen 32 alternately in two planes.

When a series of slices is cut from a paraffin block in the manner described, each completed slice adheres to the outer edge of the knife 46. The next successive slice moving downward from the cutting edge pushes the previous slice ahead of it, and during this action the edges of the slices cohere or stick together, so that a series ,of slices comes off the microtome in the form of a continuous ribbon. .Figure 6 illustrates such a ribbon comprising sections 59a., 59h, 59C, 59d, from a specimen such as 32 when out in one plane in the ordinary manner. The sections 50a, 59h, 50C, etc., are all similar to slice 59, and obviously present the aspect of the specimen only in the single plane.

Figure '7 shows a ribbon comprising successive sections 49a, 59a, 49h, 50h, etc., the sections being cut in two planes by means of the present invention. Each cross section, such as 59a, is immediately preceded by and joined to a corresponding longitudinal section 49a. For example, if a plant stem be used as a specimen, the result is a ribbon comprising alternate longitudinal and cross sections of the stem arranged in continuous order.

By the use of the invention as described, it is obviously made possible to perform interpretations of specimen structures with greater accuracy and completeness than with previous cutting devices. For example, in the case of a microscopic tissue examination of a duct or a bundle of blood vessels, the technician is enabled to examine the duct or bundle in successive cross sections as it encounters the cutting edge and then to observe the same duct or bundle in longitudinal section between its nearest cross sections in the same ribbon. The advantage of the above ability to examine a single specimen in successive and directly related cross and longitudinal sections is of especial importance in histological analysis in large hospitals and the like, since tissue is often pathic only in localized areas and no accurate interpretation could be made from sec` plane at every second revolution, the feed of the microtome`is set at one-half the desired thickness of slice.

When it is desired to render the shifting of the holder I6 automatic, the device shown in Fig. 9 is employed. A bracket 5I, secured to the head I4, carries at its extremity a pin 52. A claw 53, pivotally mounted on the pin 52, is adapted to engage the outer side of pin 28 in the segment I9 when the holder I6 is swung upward as shown. A vertical link 54 connects an extension 55 of the claw 53 with a lever 56 pivoted to an upright 51 forming part of a bracket 58 secured to the microtome base 33. A second claw 59, also pivotally mounted on the pin 52, is adapted to engage the pin 28 in segment I9 when the holder I5 is swung into downward position. A second link 69 connects an extension 6I of claw 59 with a second lever 62 pivoted to a second upright 53 on the lower bracket 5B.

A rod 64, pivotally attached to the pin 28, is slidable in a sleeve 65 pivoted on the pin 52 of bracket 5I. A spring 66 urges the rod 64 outward, thus forming a toggle combination which tends to force the holder I6 into either upper or lower position whenever the pin 28 is to the left or right respectively of the line of centers be tween the pin 52 and the tapered pivots I 'i and I8.

A cam shaft 67, journalled in a pedestal 68 on the bracket 58, is adapted to be driven at onehalf the speed of the microtome shaft 39 by any suitable means such as a chain 69 and the sprockets I9 and 1I. A cam I2 on the shaft 6'! overlies the free end of the lever 56, while a second cam 'I3 arranged at 180 degrees with cam 'i2 and offset therefrom along the shaft 91, overlies the free end of lever 62.

The operation of the automatic shifting means is as follows: Assuming the holder I6 .to be in upper cutting position, as shown in Fig. 9, during the cutting stroke and during the upward stroke of the head I4 the lever 55 swings freely below the cam 'I2 until the block 32 has cleared the knife 46. Thereafter, as the upward movement of the head I4 continues, the lever 56 encounters the lobe of cam E2 which restrains further upward motion of the lever and link 54. As the pivot pin 52 continues to move upward, the stopping of link 54 causes the claw 53 to be swung counter-clockwise, moving the pin 28 past dead center as shown in dot-and-dash lines, Fig. 9, and at the same time compressing the toggle spring 66. After the pin 28 has been forced over dead center, the spring 66 re-eXpands to continue the movement of the pin 28 until the holder I8 is swung completely into its lower cutting position.

The following downward stroke of the head I4 causes a section to be cut from the bottom of the block 3| as previously described. After the block has cleared the knife 46 on the next upward stroke the lever (i2 encounters the lobe of cam 13, the camshaft 5'IV having revolved 180 degrees since the previous engagement of lever 56 with cam 12. The upward movement of lever 62 and link 69 is thereby restrained, causing the record claw 59 to move the pin 28 upwardly and to the left past its dead center, after which the toggle spring 66 operates in the manner described to return the holder I6 to its initial cutting position as shown.

As the levers 56 and 62 are operable by separate cams set at 180 degrees, each lever is free to idle while the other is in operation, while both levers idle during the cutting strokes and during the return strokes until the block 3| has been carried above the knife 46, so that no interference between the claws or improper shifting of the holder I6 can occur. The use of the toggle as described to complete the shifting movements makes unnecessary any exact or delicate adjustment of the movements of the claws 53 and 59, and the length of links 54 and 60 is sufficiently great that the ,horizontal movement of the head I4 due to feed has no effective influence on the automatic shifting action.

From the foregoing, it is evident that the continued rotation of the microtome shaft 39 will cause the device to be shifted automatically to produce a series of sections cut alternately from two planes of the specimen and forming a continuousy ribbon as previously described.

While the invention has been described in preferred form, it is not limited to the exact structures illustrated, as various modifications may be made without departing from the scope of the appended claims.

What is claimed is:

1. In a specimen holding device for use on a microtome including a knife and a movable head cooperative therewith, in combination, a yoke, a shank on said yoke and adapted to be attached to said head, a holder pivotally mounted in said yoke, a platen adjustably secured to said holder and adapted to retain a specimen, whereby said specimen may be presented to said knife by motion of said head, means to rotate said holder and specimen between two positions in said yoke, stops onsaid holder adapted to engage said yoke whereby said positions may be pre-determined,

f and means in said shank and engaging said holder to automatically latch said holder in each of said positions. p

2. In a specimen holder for a microtome, in combination, a support,V a holding member pivotally mounted thereon and rotatable thereon between two positions through an angle of substantially ninety degrees, said member being formed with an arcuate surface having terminal notches therein, means to secure a specimen to said holder, and latching means in said support and adapted to automatically engage said notches to retain said holding means in either of said positions.

3. In a microtome having a base, in combination, a knife, means on said base to support said knife, a mounting head, means on said base to movably support said head adjacent said knife, means pivotally mounted on said head and adapted to hold a specimen, feeding means to advance said head and specimen toward said knife, means to move said head across said knife whereby sections may be cut from said specimen by said knife, means to swing said holding means back and forth through a pre-determined angle whereby said sections may be alternatelyV cut from said specimen in two non-parallel planes,

and resiliently controlled means to latch said holding means in each of two positions determining the limits of said angle.

4. In a microtome, in combination, a base, a knife, means on said base to support said knife, a mounting head movably supported on said base adjacent said knife, means pivotally mounted on said head to hold a specimen, feeding means to advance said head and specimen toward said knife, means to move said head across said knife whereby sections may be cut from said specimen by said knife, means to rotate said holding means between two predetermined cutting positions whereby two non-parallel planes of said specimen may be alternately presented to said knife, and resilient means to control said rotating means including a spring-pressed latch engaging said holding means and adapted to retain the same in each of said two positions.

5. In a specimen holding device for use on a microtome including a stationary knife and a movable head cooperative therewith, in combination, a yoke, a shank on said yoke and adapted to be attached to said head, a holder pivotally mounted in said head, means on said holder to retain a specimen whereby said specimen may be presented to said knife, means to rotate said holder and specimen between two positions in said yoke, stops on said holder adapted to engage said yoke whereby said positions may be pre-determined, and a spring-pressed latch in said yoke engaging said holder to retain the same in each of said two positions.

6. In a microtome adapted to cut successive sections from a specimen pivotally held thereon, in combination, a stationary knife, feeding means to advance said specimen toward said knife,

means to move said specimen across said knife to cut said sections, and means connected to said moving means and operable thereby to rotate said specimen back and forth through -a set angle of substantially ninety degrees whereby two substantially perpendicular planes of said specimen may be alternately presented to said knife.

7. In a microtome, in combination, a stationary knife, a movabler mounting head adjacent said knife and cooperative therewith, means on said head to hold a specimen, said holding means being pivotally mounted on said head, feeding means to advance said head, holding means and specimen toward said knife, means to move said head, holding means and specimen across said knife whereby sections may be cut from said specimen by said knife, manually operable means to rotate said holding means between two predetermined cutting positions whereby two nonparallel planes of said specimen may be alternately presented to said knife, and resilient means to latch said holding means in each of said cutting positions.

' DONALD M. CROOKS. 

